1. Field of the Invention
The present invention relates generally to medicine, more specifically to ophthalmology and has particular reference to a corrective intraocular lens which can find successful application for, e.g., treatment of myopia, hyperopia, astigmatism, and some other eye diseases.
2. Description of the Prior Art
Correction of such eyesight deficiences as myopia, hyperopia, and the like has involved the use of glasses or contact lenses. However, correction with the use of such devices is but a temporary one, since such devices must be placed and removed periodically, e.g., while skiing, swimming, etc.
Permanent correction of eyesight is performed with the aid of keratotomy, one of whose techniques includes removal of the corneal layer and its reshaping, while another technique consists in making a multiplicity of radial cuts into the corneal layer to adjust the curvature thereof, followed by healing. The aforesaid kerato-refractive surgical techniques are of the irreversible nature and suffer from inadequate accuracy of prognostication of the postoperative refractive effect.
Intraocular lenses or lenticuli have been used to solve these problems, but they are intended largely for correction of postcouching aphakia.
There has been provided a corrective lens for use in conjunction with the intact natural lens, such as that described in U.S. Pat. No. 4,585,456 issued on Apr. 29, 1986 to Blackmore. Said corrective lens employs an optical body formed of material biocompatible with the eye and having a concave posterior surface whose curvature suits that of the external surface of the natural lens. The aforesaid optical body includes a means for its positioning so as to be adjacent to the natural lens. To retain the corrective lens in said position provision is made for supporting elements shaped as e.g., open loops associated with the positioning means as is known in the art with respect to intraocular lenses. When inserting such a corrective lens within the patient's eye the supporting elements are placed in the ciliary sulcus. However, such an attachment is subject to all disadvantages inherent in fastening of an intraocular lens in the ciliary sulcus, in particular, the danger, and rather frequent, of inflammations of the ocular tissues. Moreover, as it has been confirmed by practical experience, such an attachment might be inadequately reliable and results in dislocation or displacement of the corrective lens.